The Pre-exposure Prophylaxis (PrEP) for the prevention of human immunodeficiency virus (HIV) infection consists in using antiretroviral medicine before sexual exposure to the virus to decrease probability of infection. The PrEP is capable of preventing the virus infection and promoting a healthier sexual life. Brazil has been a reference in HIV treatment not only because it was the first country in Latin America to offer free antiretroviral treatment to virus carriers but also because it participated in the Initiative in Pre-exposure Prophylaxis (iPrEP), a study that was carried out in several countries worldwide and proved effectiveness of the PrEP. Medication distributed by the Brazilian Public Health System (SUS) is quite unknown to the population. To mitigate current proliferation of sexually transmitted diseases (STDs) and increase in pregnancy cases among adolescents, sexual orientation has been intensified in schools and, thus, it has also become their responsibility, rather than parents’ responsibility alone. Therefore, this study aimed at carrying out dynamic and dialogic interventions about the PrEP in classes taught to High School seniors who attend technical courses in Commerce and in Development of Digital Games at the Instituto Federal do Triângulo Mineiro - Campus Uberlândia Centro, Uberlândia, Minas Gerais (MG), Brazil. A dialogical Chemistry class was taught to show students several images and chemical structures of active ingredients found in the medication (PrEP). Besides, students answered a questionnaire with open questions anonymously to evaluate the effect of the class on their learning about sexual education, HIV/AIDS and, mainly, the PrEP. Students showed much interest in the tasks and interacted positively. Results of the questionnaire enabled to observe students’ increase in knowledge about the PrEP. In sum, this study enabled the PrEP to be better disseminated, since doubts were mitigated.